package org.wlgzs.office_exam_student.servlet;

import org.wlgzs.office_exam_student.util.VerifyCodeUtils;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;

/**
 * Copyright (C), 2016-2018, 孤城落寞的博客
 * FileName: AuthImageServlet
 * Author:   gclm
 * Date:     2018/1/25 下午3:15
 * Description: AuthImageServlet
 */
@WebServlet("/login-vcode")
public class AuthImageServlet extends javax.servlet.http.HttpServlet implements javax.servlet.Servlet {
    static final long serialVersionUID = 1L;

    public void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        response.setHeader("Pragma", "No-cache");
        response.setHeader("Cache-Control", "no-cache");
        response.setDateHeader("Expires", 0);
        response.setContentType("image/jpeg");
        //生成随机字串
        String verifyCode = VerifyCodeUtils.generateVerifyCode(4);
        //存入会话session
        HttpSession session = request.getSession(true);
        //删除以前的
        session.removeAttribute("verCode");
        session.setAttribute("verCode", verifyCode.toLowerCase());
        //生成图片
        int w = 100, h = 38;
        VerifyCodeUtils.outputImage(w, h, response.getOutputStream(), verifyCode);

    }
}
